Medical treatment of several illnesses requires continuous drug infusion into various body compartments, such as subcutaneous and intra-venous injections. Diabetes mellitus (DM) patients, for example, require the administration of varying amounts of insulin throughout the day to control their blood glucose levels. In recent years, ambulatory portable insulin infusion pumps have emerged as a superior alternative to multiple daily syringe injections of insulin, initially for Type 1 diabetes patients (Diabetes Medicine 2006; 23(2):141-7) and consecutively for Type 2 (Diabetes Metab Apr. 30, 2007 Diabetes Obes Metab Jun. 26, 2007). These pumps, which deliver insulin at a continuous basal rate as well as in bolus volumes, were developed to liberate patients from repeated self-administered injections, and allow them to maintain a near-normal daily routine. Both basal and bolus volumes must be delivered in precise doses, according to individual prescription, since an overdose or under-dose of insulin could be fatal.
The first generation of portable infusion pumps concerns “pager-like” devices with a reservoir contained within the device's housing. A long tube delivers insulin from the pump attached to a patient's belt to a remote insertion site. Both basal and bolus volumes deliveries in these “pager-like” devices are controlled via a set of buttons provided on the device. A screen/display is provided on the device housing providing the user with fluid delivery status, programming flow delivery, alerts and alarms. Such devices are disclosed, for example, in U.S. Pat. Nos. 3,771,694, 4,657,486 and 4,498,843. These devices represent a significant improvement over multiple daily injections, but nevertheless, they all suffer from several major drawbacks, among which are the large size and weight, long tubing and lack of discreetness.
To avoid the consequences of long delivery tube, a new concept on which a second generation pumps are based, was proposed. As described in prior art, the new concept concerns a remote controlled skin adherable device with a housing having a bottom surface adapted for contact with the patient's skin, a reservoir disposed within the housing, and an injection needle adapted for communication with the reservoir. The user interface means can be represented by a remote controller that contains operating buttons and screen/display providing fluid delivery status, programming flow delivery, alerts and alarms. This paradigm was described, for example, in U.S. Pat. Nos. 5,957,895, 6,589,229, 6,740,059, 6,723,072 and 6,485,461.
These second generation devices also have several limitations; they are heavy and bulky, not detachable, and expensive because the entire device should be discarded every 2-3 days. Another major drawback of these 2nd generation skin adherable devices concerns the remote controlled drug administration. The user is totally dependent on the remote control and cannot initiate bolus delivery or operate the device if the remote control is not at hand, lost or has malfunctioned (practically, the patient cannot eat).
A third generation of skin adherable infusion devices was devised to avoid the price limitation and to extend patient customization. An example of such a device was described in our previous patent applications U.S. Ser. No. 11/397,115 and PCT/IL06/001276. This third generation device contains a remote control unit and a skin adherable patch unit (also referred to as “dispensing patch unit”) that can be comprised of a reusable part and a disposable part. The reusable part can contain the metering portion, electronics, and other relatively expensive components. The disposable part can contain the reservoir and in some embodiments batteries. A tube can deliver the fluid from the reservoir to an exit port that contains a connecting lumen. This concept provides a cost-effective skin adherable infusion device and allows diverse usage such as various reservoir sizes, various needle and cannula types, etc.
Generally, the skin adherable infusion devices of third generation require a remote control. The remote control can be carried out by a remote control unit, which is a separate item. In addition to the disadvantage of being bulky and heavy, the remote control unit can be easily lost and it is one of the greatest fears of diabetic patients to loose the remote control unit, since in this situation the patient can not operate the pump to dispense insulin into the body. In extreme situations, losing the remote control unit could have serious consequences for the patient's health. It is worth mentioning that skin adherable patches are known already for a relatively long time and therefore, the above-mentioned problem associated with a separate remote control unit is not new. Nevertheless, it only recently has been suggested to provide an adherable patch with a possibility for autonomous control instead of or in addition to remote control. The autonomous control is achieved by providing the patch with dedicated operating buttons/switches which allow operating the patch and thus, eliminating the necessity in separate remote control unit.
In our U.S. Provisional Patent Application No. 60/876,679, a 4th generation patch/device unit has been disclosed. The 4th generation unit can be disconnected and reconnected to the body by virtue of a skin adherable cradle unit. After reservoir filling, the process of mounting the patch unit to the patient generally includes attaching the cradle unit the skin of the patient, inserting a cannula through a cradle opening (a “well”) into the subcutaneous tissue, and connection of the patch unit to the cradle unit.
The 4th generation detachable skin adherable patch can be either remotely controlled or operated by a dedicated control button(s)/switch(es) that are located on the patch housing (preferably on the reusable part) as disclosed in our co-pending U.S. Provisional Patent Application No. 60/691,527, filed Jul. 20, 2007, and titled “Manually Operable Portable Infusion Pump”. By virtue of the 4th generation patch device, the user can deliver a desired bolus dose by repetitive pressing of control buttons (“Bolus buttons”) and the separate remote control unit is not any more necessary.
The co-pending U.S. patent application Ser. No. 11/706,606 discloses a dual function dispensing device that contains a dispensing patch/device unit (i.e. insulin dispensing patch) and an analyte sensing means (i.e. continuous glucose monitor). This dual function device can have the same configuration that was outlined above and can also be disconnected from and reconnected to the body at patient discretion.
The patch unit of the 4th generation devices does not have a screen or a display. Thus, without the remote control, the patient may not be aware of the current state of the system (real time and/or historical data). The two operating buttons/switches provided at the patch unit cannot be used for other functions. For example, configuration the operating buttons cannot be used to configure a basal rate or a bolus profile.